TOPEKA, Kan. — Kansas and Arizona officials filed a federal lawsuit on Wednesday in an attempt to force a federal elections agency to change its voter registration forms to compel proof of citizenship.

It is the latest legal effort in a nationwide battle by states seeking to crack down on voter fraud by making it harder for non-U.S. citizens to gain access to the ballot box.

The lawsuit was filed in federal court in Topeka and seeks to force the Elections Assistance Commission to modify federal voter registration forms to require documents proving citizenship. Currently the forms only require an applicant to make an oath affirming citizenship.

In Kansas, the change would bring the federal application process in line with the state's rules. Kansas Secretary of State Kris Kobach and his Arizona counterparts have been active in seeking to tighten voter registration laws, including passage of laws that require applicants to show proof of citizenship when registering to vote.

"Voting is the most cherished right of a U.S. citizenship," Kobach said. "We take seriously our obligation to protect that right and to secure that right and to guard it close so that only citizens may exercise the right to vote."

The high court ruled 7-2 that the Arizona law is pre-empted by the federal voter registration law, and the majority noted that the U.S. Constitution allows Congress to "make or alter" state rules on the times, places and manner of elections for federal offices.

Kobach maintains the ruling has no effect on the Kansas law, though the two are similar.

The Kansas proof-of-citizenship law applies when people register to vote in the state for the first time, requiring them to provide a birth certificate, passport or other documents. Elections officials must accept the registration application but residents wouldn't be eligible to vote until they provide proof of citizenship.

The Arizona statute said that election officials must reject any voter registration application that is not accompanied by proof of citizenship. The Supreme Court said that rule added a requirement for using a federal registration form not imposed by Congress.

Arizona Attorney General Tom Horne said the Supreme Court told states they could file an action with the courts if the EAC lacked enough members to act on its own, or if executive director Alice Miller didn't approve a state's request for changes.

"She's denied our request and that's exactly what we're doing," Horne said. "I fully expect us to be successful based on the Supreme Court decision. The reason it's important is because we want citizens to vote and we don't want illegal aliens to vote."

The lawsuit was assigned to U.S. District Judge Eric Melgren, a former U.S Attorney for Kansas who was appointed to the bench by President George W. Bush. Kobach said the lawsuit was filed in Kansas for financial reasons since his office will do most of the work on the case. Other options would have been to file it in Arizona or the federal court in the District of Columbia.

Paul Bender, a constitutional law professor at Arizona State University, said Arizona and Kansas will likely have an uphill battle convincing a court to order the commission to grant what the states are seeking. He said the issue is whether the states need the requirement to show proof of citizenship for voter registrations in order to administer its voter qualification standards.

"I think the state has a very weak position there, because I am not aware of any proof they have that the failure to require proof a citizenship when you register to vote has resulted in any non-citizen voting." Bender said.

Kobach said there had been a handful of instances where noncitizens tried to vote, including one case where an individual voted illegally five times during one election in southwest Kansas.